System and associated method for preventing overfilling in a dishwasher

ABSTRACT

A method, system, and computer-program product for preventing overfilling in a dishwasher are disclosed herein. According to one embodiment, a method for preventing overfilling in a dishwasher is provided, wherein the dishwasher includes a water valve for providing water to the dishwasher and a drain pump for removing water from the dishwasher. The method comprises detecting an overfill condition in the dishwasher with at least one detection device, wherein the overfill condition corresponds to a water level in the dishwasher that is greater than a predetermined threshold. The method further includes controlling the drain pump and the water valve in response to detecting the overfill condition in order to facilitate removal of the overfill condition.

FIELD OF THE INVENTION

Embodiments of the present invention relate to dishwashers and, moreparticularly, to a system and associated method for preventingoverfilling in a dishwasher.

BACKGROUND

Dishwashers have become an integral part of everyday household use.Typical dishwashers use water pumped into a tub to clean dishes andutensils. In a typical cycle there are multiple water fills withintermediate pump outs. If a malfunction occurs that results inexcessive water input or failure to pump out, flooding may occur. Manydishwashers, either with a stainless steel or a plastic tub, dependsolely upon the function of a mechanical float for physically activatinga float switch, in response to a flood condition within the tub. Ingeneral, the stem of the float extends downwardly from the float througha central opening in the switch support housing and outwardly of the tubin order to activate the float switch. As such, since the stem of thefloat must move freely through the central opening, the central openingmay be configured to be open to atmosphere inside the tub. Thisopen-to-atmosphere condition may thus create a potential path for waterto leak out of the unit.

A flood condition in the dishwasher could occur due to a singlecomponent failure or a combination of component failures. For example, asticking or otherwise defective float switch may fail to properlysignify a high water level condition and thereby cause a floodcondition. Often times, the float switch may be the sole provision fordetecting the high water level condition. In some instances,combinations of a faulty water inlet valve, a clogged drain filterand/or drain hose, and/or a faulty float switch can also cause a floodcondition.

Thus, there is a need for an effective method and system for preventingoverfilling in a dishwasher, as well as a need to diagnose potentialmalfunctions in particular components of the dishwasher causing theoverfilling.

SUMMARY OF THE INVENTION

In light of the foregoing background, embodiments of the presentinvention provide methods, systems, and computer-program products forpreventing overfilling in a dishwasher. Embodiments of a dishwasher mayadvantageously detect and remove an overfill condition in a dishwasheras well as determine which components are malfunctioning when theoverfill condition is not removed.

One embodiment is directed to a method for preventing overfilling in adishwasher, wherein the dishwasher comprises a water valve for providingwater to the dishwasher and a drain pump for removing water from thedishwasher. The method comprises detecting an overfill condition in thedishwasher with at least one detection device, wherein the overfillcondition corresponds to a water level in the dishwasher that is greaterthan a predetermined threshold. The method also comprises controllingthe drain pump and the water valve in response to detecting the overfillcondition in order to facilitate removal of the overfill condition. Themethod may further comprise controlling the drain pump and the watervalve either until the overfill condition is removed or for apredetermined amount of time. This controlling may comprise closing thewater valve and actuating the drain pump in a first pump-out cycle untilthe overfill condition is removed. Additionally, the method couldcomprise deactuating the drain pump when the overfill condition isremoved.

In another embodiment, the method further comprises executing a watervalve error routine. The water valve error routine comprises detectingan overfill condition with the detection device following the first pumpout cycle and determining the number of consecutive overfill conditionsdetected. The water valve error routine may further comprise actuatingthe drain pump in an ongoing pump out cycle until the overfill conditionis removed in response to detecting a predetermined number ofconsecutive overfill conditions. Additionally, the method could furthercomprise determining a flow rate of the water through the water valveand an elapsed time between successive pump out cycles. Finally, themethod may further comprise providing a water valve error signal inresponse to detecting a predetermined number of overfill conditions withthe detection device.

The method, in another embodiment, may further comprise executing adrain pump/detection device error routine. The drain pump/detectiondevice error routine comprises determining whether water is present inthe dishwasher with a sensing device (e.g., a turbidity sensor)following the step for controlling the drain pump and water valve for apredetermined period of time. The drain pump/detection device errorroutine may further comprise providing a detection device error signalin response to sensing no water in the dishwasher. Alternatively, thedrain pump/detection device error routine may further comprise providinga drain pump error signal in response to sensing the presence of waterin the dishwasher.

Additionally, in another embodiment, the method may further compriseexecuting a clog error routine, the clog error routine comprisingclosing the water valve and actuating the drain pump for a predeterminedperiod of time. The clog error routine may further comprise providing adrain filter or drain hose error in response to detecting an overfillcondition following the predetermined period of time.

In another embodiment, the method may further comprise detecting anoverfill condition with at least one detection device comprising a floatand a float switch, wherein the float is movable in relation to thefloat switch such that the float switch is configured to be actuatedwhen the float is activated by an overfill condition. For example, thefloat switch may be at least one magnetically actuated reed switchconfigured to be actuated in response to movement of a magnet associatedwith the float.

Another embodiment is directed to a system for preventing overfilling ina dishwasher, comprising a water valve for providing water to thedishwasher, a drain pump for removing water from the dishwasher, atleast one detection device for detecting an overfill condition in thedishwasher, wherein the overfill condition corresponds to a water levelin the dishwasher that is greater than a predetermined threshold, and acontrol device for controlling the drain pump and the water valve inresponse to detecting the overfill condition in order to facilitateremoval of the overfill condition. The detection device may comprise afloat and a float switch, wherein the float is movable in relation tothe float switch such that the float switch is configured to be actuatedwhen the float is activated by an overfill condition. Also, the floatswitch could comprise at least one magnetically actuated reed switchconfigured to be actuated in response to movement of a magnet associatedwith the float. Additionally, the system could further comprise aturbidity sensor for sensing the presence of water in the dishwasher andcommunicating with the control device.

Moreover, another embodiment is directed to a computer program productfor preventing overfilling in a dishwasher, the computer program productcomprising a computer-readable storage medium having computer-readableprogram code portions stored therein. The computer-readable program codeportions comprise a first executable portion for detecting an overfillcondition in the dishwasher with at least one detection device, whereinthe overfill condition corresponds to a water level in the dishwasherthat is greater than a predetermined threshold, and a second executableportion for controlling the drain pump and the water valve in responseto detecting the overfill condition in order to facilitate removal ofthe overfill condition.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described various embodiments of the invention in generalterms, reference will now be made to the accompanying drawings, whichare not necessarily drawn to scale, and wherein:

FIG. 1 is a perspective view of a dishwasher, wherein the dishwasher ispartially cut away, according to one embodiment of the presentinvention;

FIG. 2 is a sectional view of the inside of a dishwasher, according toone embodiment of the present invention;

FIG. 3 is a block diagram of a system for preventing overfilling indishwasher, according to one embodiment of the present invention;

FIG. 4 is a flow chart of an overfill routine for preventing overfillingin a dishwasher, according to one embodiment of the present invention;

FIG. 5 is a flow chart of a water valve error routine, according to oneembodiment of the present invention;

FIG. 6 is a flow chart of a drain pump/detection device error routine,according to one embodiment of the present invention;

FIG. 7 is a flow chart of a clog error routine, according to oneembodiment of the present invention;

FIG. 8 is a detailed flow chart of an overfill prevention routine,according to one embodiment of the present invention;

FIG. 9 is a sectional view of the inside of a dishwasher, according toone embodiment of the present invention;

FIG. 10 is a sectional view of the inside of a dishwasher, wherein anoverfill condition has occurred, according to one embodiment of thepresent invention;

FIG. 11 is a detail view of a detection device comprising magneticallyactuated reed switches, wherein an overfill condition has occurred,according to one embodiment of the present invention;

FIG. 12 is a perspective view of the inside of dishwasher showing adetection device, according to one embodiment of the present invention;

FIG. 13 is a detail view of a portion of a detection device, accordingto one embodiment of the present invention; and

FIG. 14 is a detailed view of a sensing device, according to oneembodiment of the present invention.

DETAILED DESCRIPTION

Various embodiments of present inventions now will be described morefully hereinafter with reference to the accompanying drawings, in whichsome, but not all embodiments of the inventions are shown. Indeed, theseinventions may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will satisfy applicablelegal requirements. Like numbers refer to like elements throughout.

FIG. 1 illustrates one example of a dishwasher 10 capable ofimplementing various embodiments of the present invention. Such adishwasher 10 typically includes a tub 12 (partly broken away in FIG. 1to show internal details), having a plurality of walls (e.g., side wall13) for forming an enclosure in which dishes, utensils, and otherdishware may be placed for washing. As known in the art, the dishwasher10 may also include slidable bottom and upper racks (not shown) forholding the dishes, utensils, and dishware. A door 18 may be pivotablyengaged with the tub 12 to selectively permit access to the interior ofthe tub 12. The door 18 closes to cover and seal the tub 12 when thedishwasher 10 is in operation.

The tub 12 may define a sump 14, in which wash water or rinse water iscollected, typically under the influence of gravity, wherein the sump 14may cooperate with a bottom wall 17 to enclose the dishwasher in the tub12. The wash/rinse water may be pumped by a sump pump 15 out of the sump14 to various spray arms 20 mounted in the interior of the tub 12 forspraying the wash/rinse water, under pressure, onto the dishes,utensils, and other dishware contained therein.

The sump 14 may include/define various inlet ports and outlet ports incommunication with various operational components of the dishwasher 10.For example, a water valve 50 and a drain pump 60 may each be incommunication with the sump 14 or otherwise with the dishwasher 10. Thewater valve 50 may be configured to open, or turn ON, to direct waterfrom a house supply/source to the sump 14 or otherwise to the tub 12 ofthe dishwasher 10. The water valve 50 may also be configured to close,or turn OFF, to stop directing water to the tub 12. The drain pump 60may be configured to actuate, or turn ON, to remove water from the sump14 or tub 12, as well as being configured to deactuate, or turn OFF, tostop removing water from the sump 14 or tub 12. Thus, through selectiveactuation of the water valve 50/drain pump 60, water may be selectivelyadded or removed from the dishwasher 10. The drain pump 60 and the watervalve 50 may be configured to be automatically actuated (i.e.,electrically opened and closed), though one skilled in the art willappreciate that such components may be actuated in different ways suchas, for example, mechanically, hydraulically, and/or in otherappropriate manners.

With reference to FIG. 1, particular operational components (e.g., watervalve 50, drain pump 60, corresponding hoses and wires, etc.) may behoused, disposed, or otherwise positioned within a base portion 22positioned beneath the tub 12. In some instances, the base portion 22may be a separate component with respect to the tub 12, such as, forexample, a molded polymer component, while in other instances the baseportion 22 may be integral with the tub 12 such that the side wallsforming the tub 12 also at least partially form the base portion 22.

The dishwasher 10 typically includes wash programs having variousparameters of the dishwashing process. In particular, the dishwasher 10may be in an operating mode when using these wash programs, which mayrequire providing water to the dishwasher 10 to clean dishware,utensils, or the like. Thus, with reference to FIG. 2, the dishwasher 10may at least partially fill with water provided by the water valve 50.This water may form a water level 55 inside the tub 12 of the dishwasher10. If the components of the dishwasher 10 cease to work properly toomuch water may enter or remain in the tub 12, possibly causing the waterto break the seal of the door 18 and leak outside of the tube 12 of thedishwasher 10. This situation represents an overfill condition, whichmay also correspond to the water level 55 reaching a pre-determinedthreshold level 25. In this regard, embodiments of the present inventionmay be implemented in a dishwasher 10 to more precisely monitor andcontrol the water level 55 within the dishwasher 10, so as to preventoverfilling within the dishwasher 10.

The tub 12 may comprise at least one detection device 30 for monitoringthe water level 55 and detecting an overfill condition in the tub 12. Inparticular, the detection device 30 can be configured to detect when thewater level 55 reaches the threshold level 25, thereby signaling anoverfill condition. The detection device 30 may be any type of devicethat can detect an overfill condition (e.g., a particularly placedsensor, a float, or the like) and can be located inside the tub 12 todetect the water level 55 of the dishwasher 10, as shown in FIGS. 12 and13. Also, the detection device 30 may be configured to detect removal ofthe overfill condition (e.g., when the water level 55 recedes below thethreshold level 25). In one embodiment, the detection device 30 is afloat switch assembly (see FIGS. 11 and 13, discussed below).

Additionally, a control device 40 can be used to communicate withcertain components of the dishwasher 10. The control device 40 may behoused inside the base portion 22 of the tub 12 or other location so asto facilitate communication with various components of the dishwasher10. In the depicted embodiment, the control device 40 is housed in thebase portion 22 of the tub 12 and is configured to communicate with thewater valve 50, drain pump 60, and detection device 30. In this way, thecontrol device 40 can determine whether the drain pump 60 is actuated ordeactuated and the water valve 50 is opened or closed as well as beingable to actuate or deactuate the drain pump 60 and open or close thewater valve 50. Also, the control device 40 may be configured todetermine if the detection device 30 has detected an overfill conditionor if the detection device 30 has detected removal of the overfillcondition. Furthermore, the control device 40 may be configured tocommunicate with the dishwasher 10 to determine if the dishwasher 10 isin an operating mode, and more particularly, whether the dishwasher 10requires water to be provided to it. The control device 40 may be anytype of device that can communicate with the components of thedishwasher 10, electronically, mechanically, or otherwise. In the caseof electronic communication, the control device 40 may include a memoryfor storing of programming, routines, and variables. In such a case, thecontrol device 40 may be configured to indicate or otherwise provideerror message signals by either storing them in the control device 40for later access by a user, signaling the dishwasher 10 to display theerror message to the user, or other indicating means. In one embodiment,the control device 40 is a microprocessor or other processor configuredto perform the functions described herein and may operate under thecontrol of software. The control device 40 may be configured toautomatically control the water valve and drain pump in response toreceiving a signal indicative of an overfill condition, as explained infurther detail below.

In various embodiments, the dishwasher 10 may also comprise a sensingdevice 45 for sensing the presence of water in the dishwasher 10. Thesensing device 45 can be placed anywhere in the dishwasher 10 where itis in communication with the content of the sump 14 and/or tub 12 tosense for the presence of water. For example, a pressure switch, mountedin the base, could have a capillary tube in communication with the sump.Water in the sump would pressurize the water/air in the capillary tubeproviding input to the sensor concerning water level height. In thedepicted embodiment, the sensing device 45 is located inside the sump14. The control device 40 can also communicate with the sensing device45. In some embodiments of the invention, the sensing device 45 can beused as a back-up to the detection device 30 or otherwise used forredundancy. The sensing device 45 can be any device with the ability tosense the presence of water, such as a conductivity sensor or aturbidity sensor (shown in FIG. 14). In one embodiment, the turbiditysensor can serve a dual purpose of sensing turbidity of water during anoperation mode as well as sensing the presence of water during anoverfill routine, as described below.

FIG. 3 shows a block diagram of one embodiment of a system forpreventing overfilling in a dishwasher. The system comprises a controldevice 40 configured to communicate with a water valve 50, drain pump60, and detection device 30. This system detects and removes overfillconditions in the dishwasher 10 by using a prevention routine 70 andcorresponding method for preventing overfilling in a dishwasher, asdescribed in greater detail below. The system may also comprise asensing device 45 and may diagnose errors in the components of thesystem by using any one or more of error routines 100, 200, 300 as alsodescribed below.

FIG. 4 shows a flow chart of one embodiment of a method for preventingoverfilling in a dishwasher, which is referred to herein as an overfillroutine 80. The overfill routine 80 details a method for preventingoverfilling in a dishwasher. The overfill routine 80 can be executed inresponse to detecting an overfill condition, and is not dependant on thedishwasher 10 being in an operation mode, such as washing. Additionally,program instructions containing the overfill routine 80 may be stored ina memory of the control device 40 or a computer program productotherwise in communication with the control device.

In various embodiments of the invention, the overfill routine 80comprises a prevention routine 70. As shown in FIG. 4, the preventionroutine 70 comprises detecting an overfill condition (Step 72), andcontrolling the drain pump and water valve in response to detecting theoverfill condition in order to facilitate removal of the overfillcondition. Controlling of the drain pump and water valve may continueuntil either the detection device no longer detects the overfillcondition (Step 75) or a pre-determined amount of time has passed.Additionally, controlling the drain pump and water valve could includeperforming a pump-out cycle comprising closing or turning OFF the watervalve and actuating or turning ON the drain pump (Step 73) to stopproviding water to, and start removing water from, the dishwasher. Onceeither removal of the overfill condition is detected or thepre-determined amount of time has passed, the prevention routine 70could further comprise completing the pump-out cycle by deactuating orturning OFF the drain pump (Step 76). Also, the prevention routine 70can further comprise determining if the dishwasher is in an operatingmode (Step 78) and then continuing its operating mode if necessary (Step79), such as continuing the washing cycle.

With reference to FIG. 4, the method for preventing overfilling in adishwasher may be automatically executed upon detection of an overfillcondition. For example, an overfill condition may occur when the waterlevel 55 reaches the threshold level 25. In particular, upon detectingthe water level 55 reaching the threshold level 25 (Step 72), thecontrol device 40 may receive a signal from the detection device 30indicating an overfill condition has occurred. The control device 40 maythen signal and control the water valve 50 and drain pump 60 to completeStep 73, whereby a pump-out cycle is performed in which the water valve50 is closed to stop the flow of water to the dishwasher 10 and thedrain pump 60 is actuated to encourage removal of water from thedishwasher 10. This causes the water to drain out of the dishwasher 10,thereby removing the overfill condition (i.e., the water level 55 lowersbelow the threshold level 25).

In addition, the method may further comprise detecting removal of theoverfill condition in the dishwasher (Step 75), which occurs when thedetection device 30 no longer detects the overfill condition (i.e., whenthe water level 55 is lower than the threshold level 25). Thus, when thedetection device 30 detects removal of the overfill condition, thecontrol device 40 can deactuate the drain pump 60 (Step 76), therebycompleting a pump-out cycle. This stops the drain pump 60 from operatingwhen no water is present, thus conserving energy and reducing thepossibility of damaging the pump.

Furthermore, the method may further comprise determining if thedishwasher 10 is in an operating mode, such as a washing cycle. Thus,the control device 40 can be configured to communicate with thedishwasher 10 to determine if the dishwasher 10 is in an operating modeand whether the water valve 50 should be open or turned ON (Step 78). Ifthe dishwasher 10 is in an operating mode, the control device 40 cansignal and continue the operating mode (Step 79), thereby allowing theprevention routine 70 to return the dishwasher 10 to its correctoperating mode. Thus, the prevention routine 70 can be responsivethroughout a dishwasher's 10 operating mode, and only briefly interruptthe operating mode when necessary.

With reference to FIGS. 4 and 5, in another embodiment, the overfillroutine 80 can further comprise a water valve error routine 100 fordetecting errors that may occur in the water valve 50 during orfollowing a prevention routine 70. The water valve error routine 100comprises determining the number of times an overfill condition has beendetected (Step 110) and determining if an overfill condition has beendetected following a pre-determined number of pump-out cycles (Step115). If the overfill condition has been detected following Xconsecutive pump-out cycles, the water valve error routine 100 initiatesan ongoing pump out cycle (Step 120). The ongoing pump out cycleincludes turning the water valve OFF or keeping the water valve closedand then cycling the drain pump ON (Step 130) and OFF (Step 140) untilthe fault is cleared.

In particular, the water valve error routine 100 monitors how often anoverfill condition is occurring in the dishwasher 10. Thus, if theprevention routine 70 continuously initiates pump-out cycles to removeoverfill conditions, there may be a malfunction with the water valve 50.Therefore, after X pump-out cycles running consecutively, the watervalve error routine 100 would initiate an ongoing pump-out cycle (Step120). X can be any pre-determined number (e.g., 2, 3, 4, etc.). Forexample, the water valve error routine 100 could detect the preventionroutine 70 initiating three consecutive pump-out cycles and then inresponse, initiate an ongoing pump-out cycle. The ongoing pump out cyclecan be used to repeatedly drain the dishwasher 10 of water until thewater valve fault is cleared or the overfill condition is otherwiseremoved (Step 150).

The water valve error routine 100 may also comprise determining the flowrate of water through the water valve (Step 160). Additionally, thewater valve error routine 100 could determine the amount of time thatelapses between pump-out cycles or between detection and removal of theoverfill condition (Step 165). The control device 40 can thereby set theongoing pump-out cycle to correspond to the amount of water beingreleased by the water valve 50 into the dishwasher 10 over the period oftime determined between detection and removal of the overfill condition.The period of time between actuating/deactuating the water valve and/ordrain pump could alternatively be used in conjunction with the flowrate. Moreover, the water valve error routine 100 may also compriseproviding a WATER VALVE ERROR signal (Step 180), which could be anyperceptible signal provided to a user (e.g., an audible or a visualalarm).

FIGS. 4 and 6 show another embodiment of the invention, wherein theoverfill routine 80 may also comprise a drain pump/detection deviceerror routine 200 for detecting errors that may occur in the drain pump60 or detection device 30. The drain pump/detection device error routine200 comprises determining whether water is present in the dishwasherfollowing a pre-determined time equal to ¥ elapsing following initiationof a pump-out cycle (Step 215). It should be noted that the time ¥ couldelapse before or after completion of the pump-out cycle, whethercompletion occurs due to either the detection device detecting removalof the overfill condition or the pre-determined amount of time forcompletion of the pump-out cycle elapsing. Either way, after time ¥ haselapsed, the drain pump/detection device error routine 200 comprisessensing for the presence of water (Step 220). If the sensing device 45senses water, then a malfunction in the drain pump 60 has occurred (Step245) because the drain pump 60 was unable to properly remove the waterin the pre-determined duration. Therefore, the drain pump 60 may not beworking properly or may be clogged. In this case, the drainpump/detection device error routine 200 may further comprise providing aDRAIN PUMP ERROR signal (Step 285) (e.g., an audible or a visiblesignal). Alternatively, if the sensing device 45 does not sense thepresence of water following the pre-determined duration, then amalfunction in the detection device 30 has occurred (Step 240) becausethe water and overfill condition has been removed, but the detectiondevice 30 failed to detect this removal. In this case, the drainpump/detection device error routine 200 may further comprise providing aDETECTION DEVICE ERROR signal (Step 280) (e.g., an audible or a visiblesignal). ¥ may be customizable as any pre-determined length of time(e.g., 1.7 seconds, 2 seconds, 4 minutes, etc.) that is deemedsufficient to remove the overfill condition.

In another embodiment, shown in FIGS. 4 and 7, the overfill routine 80may also comprise a clog error routine 300 for detecting errors in thedrain pump 60, which may be a clog in the drain filter or drain hose ofthe drain pump 60. The clog error routine 300 comprises determining ifan overfill condition is present (Step 320) following initiation of apump-out cycle (i.e., closing the water valve and actuating the drainpump) for a pre-determined time £ (Step 315). £ is customizable as anypre-determined length of time (e.g., 1.3 seconds, 3 seconds, 5 minutes,etc.) deemed sufficient to remove the overfill condition, and the time £could elapse before or after completion of the pump-out cycle. Thus, theclog error routine 300 determines if the detection device is activatedor otherwise still indicating an overfill condition following thepre-determined time £. If the detection device is still activated, theclog error routine 300 may further comprise providing a DRAIN FILTER orDRAIN HOSE ERROR signal (Step 380) (e.g., an audible or a visiblesignal).

Referring to FIG. 4, the overfill routine 80 may therefore comprise theprevention routine 70 alone or in combination with any one or more ofthe error routines 100, 200, 300, such as those described above. Assuch, the method for preventing overfilling in a dishwasher iscustomizable and adaptable to respond to various overfill conditions. Inone particular embodiment, as shown in FIG. 8, an overfill preventionroutine 400 comprises a prevention routine, a water valve error routine,and a drain pump/detection device error routine. In the depictedembodiment, upon detection of an overfill condition (i.e., the floatswitch trips (Step 410)) the overfill prevention routine 400 firstdetermines if a drain pump, water valve, or float switch error (Step441, 451, 461) currently exists and if the dishwasher is in an operatingmode (Step 412). If the dishwasher is washing, the washing is paused(Step 413), and the overfill prevention routine 400 takes a turbidityreading of the water (Step 414). Then, the overfill prevention routine400 actuates the drain pump (Step 415) until the float switch detectsremoval of the overfill condition (Step 420) in which it deactuates thedrain pump after a pre-determined amount of time (Step 425). If thefloat switch does not re-detect an overfill condition (Step 470) and apre-determined fill wait time has passed (Step 405), then the overfillprevention routine 400 determines if the dishwasher was previouslywashing in an operating mode (Step 406). If the dishwasher was washing,then washing is resumed (Step 407), but if the dishwasher was notwashing, then a False Alarm occurs and the overfill prevention routine400 is exited.

However, should the float switch re-detect an overfill condition (i.e.,the float switch trips again (Step 470)), the pump-out cycle isre-initiated by actuating the drain pump (Step 415) until the floatswitch un-trips and signals removal of the overfill condition (Step420). This process can repeat, and the overfill prevention routine 400also includes executing a water valve error routine upon the fourthconsecutive detection of an overfill condition (i.e., the float switchtrips and un-trips for the fourth time consecutively) (Step 470). Then,the overfill prevention routine 400 cancels the wash (Step 475) anddrains for a pre-determined amount of time (i.e., turning the drain pumpON (Step 480)). Finally, the overfill prevention routine 400 provides awater valve error signal (Step 450).

Furthermore, the overfill prevention routine 400 also comprisesexecuting a drain pump/detection device error routine upon apre-determined amount of time passing after detecting the overfillcondition (i.e., the float switch tripping) and before detecting removalof the overfill condition (i.e., the float switch un-tripping) (Step430). If this occurs, the overfill prevention routine 400 cancels thewash (Step 431) and senses for the turbidity of water with the turbiditysensor (Step 435). If water is sensed, the overfill prevention routine400 provides a drain pump error signal (Step 440). Alternatively, ifwater is not sensed, the overfill prevention routine 400 provides afloat switch error signal (Step 460).

With reference to FIGS. 9-13, the detection device 30 may comprise afloat switch assembly. In particular, the float switch assembly maycomprise a float 34, float post 36, and float switch 38 for detectingthe water level 55 inside the dishwasher 10. As illustrated by FIGS. 9and 10, the float 34 can be configured to rise and fall with the waterlevel 55 with respect to the float post 36. The float switch 38 may beconfigured to interact with the float 34, such that when the float 34rises to the threshold level 25 indicating an overfill condition, thefloat switch 38 signals to the control device 40 that an overfillcondition has occurred.

One embodiment of the present invention uses a detection device 30comprising a float switch assembly with a sealed construction. As shownin FIGS. 11-13, the float switch assembly can be located in the base ofthe tub and outside of the sump. The sealed construction of the floatswitch assembly does not have an opening leading to outside thedishwasher 10, thereby eliminating any paths for water to leak out ofthe unit. This float switch assembly can be configured in a sealedconstruction comprising a magnetically actuated reed switch 38. Inparticular, as depicted in FIG. 11, at least one magnetically actuatedreed switch 38 can be associated with the float post 36. Additionally,at least one magnet 32 can be associated with the float 34. Thus, themagnetically actuated reed switch 38 can sense the magnet 32 on thefloat 34, such that when the float 34 rises to the threshold level 25,the float switch 38 no longer senses the magnet 32 and thereby signalsto the control device 40 that an overfill condition has occurred. Invarious embodiments, the float switch 38 is configured to open andclose. In particular, the float switch 38 opens when it no longer sensesthe magnet 32 (e.g., detects an overfill condition) and closes when itsenses the magnet 32 (e.g., detects removal of the overfill condition).As such, the float switch can be configured to actuate or open when thefloat is activated by rising with the water level to the thresholdlevel, thereby indicating an overfill condition. In the depictedembodiment, the detection device 30 comprises a float switch assemblythat utilizes two magnetically actuated reed switches 38. The at leastone magnetically actuated reed switch 38 can be any magneticallyactuated switch, such as a magnetically actuated reed switch or otherelectrically actuated device with a sealed construction. However, thesealed switch 38, may be any magnetically, electrically, or opticallyactuated device, which reduces any potential for mechanical failure ofthe detection device.

According to one aspect of the invention, all or a portion of the systemgenerally operates under control of a computer program product. Thecomputer program product for performing the methods of embodiments ofthe invention includes a computer-readable storage medium, such as thenon-volatile storage medium, and computer-readable program codeportions, such as a series of computer instructions, embodied in thecomputer-readable storage medium.

In this regard, FIGS. 3-8 are flowcharts of methods, systems and programproducts according to the invention. It will be understood that eachblock or step of the flowchart, and combinations of blocks in theflowchart, can be implemented by computer program instructions. Thesecomputer program instructions may be loaded onto a computer, processor,or other programmable apparatus to produce a machine, such that theinstructions which execute on the computer, processor, or otherprogrammable apparatus create means for implementing the functionsspecified in the flowchart block(s) or step(s). These computer programinstructions may also be stored in a computer-readable memory that candirect a computer, processor, or other programmable apparatus tofunction in a particular manner, such that the instructions stored inthe computer-readable memory produce an article of manufacture includinginstruction means which implement the function specified in theflowchart block(s) or step(s). The computer program instructions mayalso be loaded onto a computer, processor, or other programmableapparatus to cause a series of operational steps to be performed on thecomputer, processor, or other programmable apparatus to produce acomputer implemented process such that the instructions which execute onthe computer, processor, or other programmable apparatus provide stepsfor implementing the functions specified in the flowchart block(s) orstep(s).

Accordingly, blocks or steps of the flowchart support combinations ofmeans for performing the specified functions, combinations of steps forperforming the specified functions and program instruction means forperforming the specified functions. It will also be understood that eachblock or step of the flowchart, and combinations of blocks or steps inthe flowchart, can be implemented by special purpose hardware-basedcomputer systems which perform the specified functions or steps, orcombinations of special purpose hardware and computer instructions.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

That which is claimed:
 1. A method for preventing overfilling in adishwasher, wherein the dishwasher comprises a water valve configured toprovide water to the dishwasher and a drain pump configured to removewater from the dishwasher, the method comprising: detecting an overfillcondition in the dishwasher with at least one detection device, theoverfill condition corresponding to a water level in the dishwasher thatis greater than a predetermined threshold; executing a pump-out cycle inresponse to detecting the overfill condition, wherein the pump-out cyclecomprises actuating the drain pump and deactuating the water valve inorder to facilitate removal of the overfill condition; determining ifthe overfill condition has been removed; and executing at least oneerror routine to diagnose an error in at least one component of thedishwasher in response to determining that the overfill condition hasnot been removed, wherein the at least one error routine comprisesexecuting a water valve error routine, the water valve error routinecomprising: determining if a threshold number of consecutive overfillconditions have been detected; and executing, in response to determiningthat the threshold number of consecutive overfill conditions has beendetected, an ongoing pump-out cycle until the overfill condition isremoved.
 2. The method according to claim 1, wherein executing thepump-out cycle comprises executing the pump-out cycle: i.) until theoverfill condition is removed, or ii.) for a predetermined amount oftime.
 3. The method according to claim 1 further comprising deactuatingthe drain pump when the overfill condition is removed.
 4. The methodaccording to claim 1, wherein executing the water valve error routinefurther comprises: determining a flow rate of the water through thewater valve and an elapsed time between successive pump-out cycles; andsetting the ongoing pump-out cycle to correspond to the flow rate of thewater through the water valve and the elapsed time between successivepump-out cycles.
 5. The method according to claim 1, wherein executingthe water valve error routine further comprises providing a water valveerror signal in response to determining that the threshold number ofconsecutive overfill conditions has been detected.
 6. The methodaccording to claim 1, wherein executing the at least one error routinecomprises executing a drain pump/detection device error routine, thedrain pump/detection device error routine comprising: determining, inresponse to determining that the overfill condition has not beenremoved, if water is present in the dishwasher with a sensing devicefollowing execution of the pump-out cycle for a predetermined period oftime.
 7. The method according to claim 6, wherein the drainpump/detection device error routine further comprises providing adetection device error signal in response to sensing no water in thedishwasher.
 8. The method according to claim 6, wherein the drainpump/detection device error routine further comprises providing a drainpump error signal in response to sensing the presence of water in thedishwasher.
 9. The method according to claim 6, wherein the determiningstep comprises determining whether water is present in the dishwasherwith a sensing device comprising a turbidity sensor.
 10. The methodaccording to claim 1, wherein executing the at least one error routinecomprises executing a clog error routine, the clog error routinecomprising: executing the pump-out cycle for a predetermined period oftime; and determining if the overfill condition has been removed afterthe predetermined period of time.
 11. The method according to claim 10,wherein the clog error routine further comprises providing a drainfilter error signal or a drain hose error signal in response todetermining that the overfill condition has not been removed after thepredetermined period of time.
 12. The method according to claim 1,wherein the detecting step comprises detecting an overfill conditionwith at least one detection device comprising a float and a floatswitch, wherein the float is movable in relation to the float switchsuch that the float switch is configured to be actuated when the floatis activated by an overfill condition.
 13. The method according to claim12, wherein detecting comprises detecting an overfill condition with atleast one magnetically actuated reed switch configured to be actuated inresponse to movement of a magnet associated with the float.
 14. A systemfor preventing overfilling in a dishwasher, the system comprising: awater valve configured to provide water to the dishwasher; a drain pumpconfigured to remove water from the dishwasher; at least one detectiondevice configured to detect an overfill condition in the dishwasher, theoverfill condition corresponding to a water level in the dishwasher thatis greater than a predetermined threshold; and a control deviceconfigured to execute a pump-out cycle in response to detecting theoverfill condition, wherein the pump-out cycle comprises actuating thedrain pump and deactuating the water valve in order to facilitateremoval of the overfill condition, wherein the control device is furtherconfigured to determine if the overfill condition has been removed andexecute at least one error routine to diagnose an error in at least onecomponent of the dishwasher in response to determining that the overfillcondition has not been removed, wherein the at least one error routinecomprises executing a water valve error routine, the water valve errorroutine comprising: determining if a threshold number of consecutiveoverfill conditions have been detected; and executing, in response todetermining that the threshold number of consecutive overfill conditionshas been detected, an ongoing pump-out cycle until the overfillcondition is removed.
 15. The system according to claim 14, wherein theat least one detection device comprises a float and a float switch,wherein the float is movable in relation to the float switch such thatthe float switch is configured to be actuated when the float isactivated by an overfill condition.
 16. The system according to claim 5,wherein the float switch comprises at least one magnetically actuatedreed switch configured to be actuated in response to movement of amagnet associated with the float.
 17. The system according to claim 14further comprising a turbidity sensor for sensing the presence of waterin the dishwasher and communicating with the control device.
 18. Acomputer program product for preventing overfilling in a dishwasher,wherein the dishwasher comprises a water valve configured to providewater to the dishwasher and a drain pump configured to remove water fromthe dishwasher, the computer program product comprising a non-transitorycomputer-readable storage medium having computer-readable program codeportions stored therein, the computer-readable program code portionscomprising: a first executable portion configured to detect an overfillcondition in the dishwasher with at least one detection device, theoverfill condition corresponding to a water level in the dishwasher thatis greater than a predetermined threshold; a second executable portionconfigured to execute a pump-out cycle in response to detecting theoverfill condition, wherein the pump-out cycle comprises actuating thedrain pump and deactuating the water valve in order to facilitateremoval of the overfill condition; a third executable portion configuredto determine if the overfill condition has been removed; and a fourthexecutable portion configured to execute at least one error routine todiagnose an error in at least one component of the dishwasher inresponse to determining that the overfill condition has not beenremoved, wherein the at least one error routine comprises executing awater valve error routine, the water valve error routine comprising:determining if a threshold number of consecutive overfill conditionshave been detected; and executing, in response to determining that thethreshold number of consecutive overfill conditions has been detected,an ongoing pump-out cycle until the overfill condition is removed. 19.The system according to claim 14, wherein executing the at least oneerror routine comprises executing a drain pump/detection device errorroutine, the drain pump/detection device error routine comprising:determining, in response to determining that the overfill condition hasnot been removed, if water is present in the dishwasher with a sensingdevice following execution of the pump-out cycle for a predeterminedperiod of time.
 20. The system according to claim 14, wherein executingthe at least one error routine comprises executing a clog error routine,the clog error routine comprising: executing the pump-out cycle for apredetermined period of time; and determining if the overfill conditionhas been removed after the predetermined period of time.